Limit the amount of escaping variables

Calculate more exactly which variables can
be referenced from an inner context, and convert
all the non escaping ones to temporaries on the
stack.

Change-Id: I0e33e85b0f6f426ef2812b8ecccee1870492b7b5
Reviewed-by: Erik Verbruggen <erik.verbruggen@qt.io>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/qml/compiler/qv4compilerscanfunctions.cpp b/src/qml/compiler/qv4compilerscanfunctions.cpp
index 2a217fbb99..b59beb0315 100644
--- a/src/qml/compiler/qv4compilerscanfunctions.cpp
+++ b/src/qml/compiler/qv4compilerscanfunctions.cpp
@@ -305,6 +305,13 @@ void ScanFunctions::endVisit(FunctionDeclaration *)
     leaveEnvironment();
 }
 
+bool ScanFunctions::visit(TryStatement *)
+{
+    // ### should limit to catch(), as try{} finally{} should be ok without
+    _context->hasTry = true;
+    return true;
+}
+
 bool ScanFunctions::visit(WithStatement *ast)
 {
     if (_context->isStrict) {
@@ -312,6 +319,7 @@ bool ScanFunctions::visit(WithStatement *ast)
         return false;
     }
 
+    _context->hasWith = true;
     return true;
 }
 
@@ -436,6 +444,11 @@ void ScanFunctions::calcEscapingVariables()
                 c = c->parent;
             }
         }
+        Context *c = inner->parent;
+        while (c) {
+            c->hasDirectEval |= inner->hasDirectEval;
+            c = c->parent;
+        }
     }
 
     static const bool showEscapingVars = qEnvironmentVariableIsSet("QV4_SHOW_ESCAPING_VARS");